In the present study, robust, versatile and straightforward strategy for the diversity-oriented convergent synthesis of a vast range of highly functionalized and biologically effective chromenes is introduced with the reaction of malononitrile, dimedone/cyclohexadione/4-hydroxycoumarin and benzaldehydes in the presence of [γ-Fe2O3@HAp-Si(CH2)3BF4@DMIM] as the catalyst. The structures of all the newly synthesized products were characterized by spectroscopic (FT-IR, 1H NMR, 13C NMR) and elemental analyses. This method benefits from several advantages such as using easily recoverable magnetic nanocatalyst, simple workup, short reaction time and excellent yields. The prepared nanoparticles were fully characterized by various spectroscopic, thermal and magnetic analyses. The catalyst exhibited good reusability feature and no loss of activity was observed even after 8 successive runs. Manuscript profile

Densely functionalized 3,4-dihydropyridones were synthesized by a four-component reaction of Meldrumʼs acid, ethyl acetoacetate, ammonium acetate, and proper aromatic aldehydes in the presence of novel organic-inorganic cobalt incorporated magnetic nanocatalyst (γ-Fe2O3@HAp/Co(II)) using ethanol as a green solvent at reflux condition. This new synthetic method provided the target compounds in a high yield (70-95%) and lower reaction time (20-75 min). The protocol benefits from the high purity of the products, environmentally friendly, milder reaction conditions, recyclability of the catalyst, and facile workup procedure. The structure of the synthesized novel nanocatalyst was confirmed by FT-IR, XRD, FSEM, TEM, EDS, and TGA analyses. The catalyst was used in eight cycles without any notable variation in catalytic activities. Manuscript profile